Figure 2. Recombinant VapA^32-189 enhances intracellular persistence of nonpathogenic E. coli in J774A.1 cells.

J774A.1 macrophage monolayers were incubated overnight with either media (triangles) or 150 nM recombinant Vap protein (VapA, circles; VapG, crosses), and infected with E. coli. Symbols delineate the mean bacterial number and bars denote the mean percent survival. The error bars represent the standard deviation calculated using a two-way ANOVA via the Holm-Sidak method. Each experimental condition was performed in triplicate per infection; n = 3. (A) Statistical significance is expressed as letters to the right of the curve, with same letters defining a lack of significant difference, and different letters defining significance with P ≤ 0.05. (B) Percent of viable E. coli cells detected, as compared to 1 hour post infection (HPI) is shown; ns = not significant; (***) = P < 0.001.